Calculating machine



June 9, 1936. 2' w A L 2,043,221

' CALCULATING MACHINE Original Filed May 31, 1950 2 Sheets-Sheet 1 ATTORNEY,

June 9, 1936. w. BALL CALCULATING MACHINE Original Filed May 31, 1950 2 Sheets-Sheet 2 R m2 W EM V I; Z

Patented June 9, 1936 UNITED STATES PATENT OFFICE CALCULATING MACHINE William Ball, Wallington, England, assignor, by

direct and mesne assignments, to British Adding and Calculating Machines Limited. London, England '7 Claims.

This invention relates to calculating machines and is a division from application Serial No. 458,629 filed 31st May, 1930, Patent No. 1,930,870, granted October 17, 1933, wherein differentially geared actuating and setting mechanism is employed for the totalizer wheels, that is mechanism wherein the actuating member is differentially movable with respect to the associated setting element.

Such actuating and setting mechanism is particularly advantageous inasmuch that transfer between adjacent totalizer wheels can be effected through the actuating and setting mechanism associated with the totalizer wheel of higher denomination, the mechanism of each denominational section including normal stationary transfer members which may be displaced for transfer, either during or subsequent to the setting of the totalizer wheels in any one cycle of the main shaft during its operation.

It is often necessary, however, in machines of the kind above referred to, to take a clearing or spacing stroke between successive cycles in order to restore displaced transfer members, so as to avoid an incorrect setting of the totalizer wheels, when it is required to accumulate the next item thereon, and it is the main object of the present invention to avoid the necessity of such clearing strokes.

According to the invention, means are provided which are operable from the main shaft of the machine to reset displaced transfer members during each cycle of the main shaft, together with means which latch the members in the reset position. By this arrangement the actuating mechanism is completely restored after each cycle of the main shaft so that it is unnecessary to take a clearing stroke when changing from addition to subtraction or total taking in successive cycles while operating the machine.

The invention will be better understood with reference to the following detailed description, taken in conjunction with the accompanying drawings, in which the invention is shown applied to the form of calculating machine, illustrated in the parent case, only those figures being shown which are deemed necessary for a complete understanding of the structure claimed. It will be understood, however, that the features of this invention are not limited specifically to the adding and subtracting form of machine shown.

In the drawings,

Fig. 1 is a detail part perspective view showing more particularly the means for resetting the transfer rack of one calculating unit, the nonessential parts being omitted for clearance;

Fig. 1 is a fragmentary figure showing in side elevation the elements shown in perspective at the right hand side of Fig. 1;

Fig. 2 is a view from the left of a calculating unit detached, the column showing nine numeral keys in addition to the column release key at the extreme right hand end and corresponding to one of the pounds columns in the machine;

Fig. 3 is a corresponding view from the right of the same unit with type bar omitted and the totalizer wheel disengaged from the actuating rack to clearly indicate the normal position thereof when the unit is mounted in the machine.

Referring now to the drawings, the machine comprises a number of detachable calculating units l2 each of which consists of a stretcher plate 28 carrying a key column including numeral keys 32 and a column release key 32a which in the normal position shown is depressed to engage the first abutment on the setting rack 58 hereinafter described, the arrangement being such that when a numeral key is depressed the column release key is released to permit the setting rack to move to engage the depressed numeral key. The operation of the numeral and column release keys is clearly described in the parent case.

Each calculating unit is provided with a totalizer wheel 20, and differentially geared actuating and setting mechanism for the totalizer wheel.

The totalizer wheel 20 is carried on a spindle 89a mounted on the bell crank 90 and moving within a slot 90a in the stretcher plate 28. The bell crank 90 is pivoted to the stretcher plate 28 at 9i, and is arranged for actuation by a transverse bail H39 which engages a slot 92 in said bell crank cc to throw the totalizer wheel 20 into engagement with the actuating rack 56--hereafter referred toduring its return stroke for addition, the wheel 29 being normally held out of engagement with the rack 56 and its setting being held by a lug 93 which projects from the left face of the stretcher plate 28 and forms a looking and alignment pawl by engaging the teeth of the pinion 68 of the totalizer wheel 20 (see Figure 3).

The spindle 89a normally abuts against the top face of the slot 90a and upon the bell crank 90 being operated by the bail I40 moves until it abuts against the lower face of the slot. This slot, therefore, determines the radial movement of the bell crank arm carrying the totalizer wheel 20 and the mesh of the pinion 68 with the actuating rack. The mechanism by which the bail M0 is actuated may be found in the parent case and is not herein described as it does not form part of the present invention.

With reference now to the differentially geared actuating and setting mechanism for the totalizer wheel 26, the stretcher plate 28 is provided with a number of slots 5!, 52, 54, 44a and 44b, which form guides for mounting the mechanism, which comprises an upper normally movable rack 53 provided with headed pins 69 riding in the slots 5|, 52, a normally stationary lower rack 51, hereinafter referred to as a transfer rack, provided with headed pins 44 riding in the slots 54a and 441) a linearly movable pinion 55 engaging with both the upper rack 53 and the transfer rack 51, the pinion being carried on a pin 55a riding in the slot 54, the actuating rack 55 formed with a slot 56 engaging with a headed pin 61 mounted on the stretcher plate 28, the rack 56 being mounted at its forward end on the pin 55a of the pinion 55, and a setting rack 53 pivoted at 59 on the upper rack 53.

With this arrangement it will be seen that the movement of the upper rack 53 is in all cases double that of the pinion 55 when the transfer rack 5'1 is stationary, and consequently double the movement of the actuating rack 55, and in this manner a well spaced keyboard may be attained, and, as described hereinafter, transfer may be eifected through the actuating mechanism during the setting of the totalizer wheels 20.

The free end of the setting rack 58 is provided with a stub 5!! arranged to ride in an inclined guide slot 5! formed in the body 5?. of the actuating rack 56, the arrangement being such that during the movement of the differentially geared mechanism from the zero position illustrated, the setting rack rises towards the keyboard by means of the guide slot 6! and the differential movement between the actuating rack 55 and the upper rack 53, it being understood that since the upper rack 53, and therefore the setting rack 58, gains on the actuating rack 56, the stub 55 and the rear end of the setting rack 58 will be caused to ride up the inclined slot 6| in the actuating rack 56.

Along the setting rack 58 are provided a number of abutments 63 which are arranged so that the forward or right hand abutment 53, seen in Figure 2, co-operates with the O or column release key 3212, the second abutment with the 1 key, and so on, the last or left hand abutment co-operating with the 8 key, and the end of the slot 6| in the actuating rack 55 being employed as the final or 9 abutment corresponding with the full travel of the setting rack 58, and thereby eliminating the necessity for a further abutment on such setting rack, although, if desired, of course, such an abutment could be provided to co-operate with the stub of the 9 key.

64 is a coil spring connected between the end of the setting rack 58 and a pin 55 on the actuating rack 56, which spring actuates the transfer rack 51 for addition transfer and also renders the differentially geared mechanism substantially self-acting by reason of the fact that the spring is normally in tension as will be explained later.

It will be understood that for a pence column twelve keys will be provided, and correspondingly eleven or twelve abutments 63, according to whether the end of the slot 6! is employed as a limit or not, and that the number of keys and co-operating abutments is adapted to the requirements of each particular case, the particular unit illustrated being one of the pounds columns of the pounds, shillings and pence machine illustrated as the preferred embodiment.

The elements of the differentially geared actuating and setting mechanism are shown in the normal or zero position, the 0 or column release key 32a at the right of the column being depressed and engaging its abutment to maintain the setting rack 58 and the remainder of the mechanism therein.

Movement of the above mechanism after a key 32 has been depressed, is controlled from the main operating shaft I of the machine through an operating member constituted by a rocker 1U pivoted to a shouldered pin "H at the foot of the stretcher plate 28, and having three arms, the first 12 being provided with an anti-friction roller 13 which when the unit is assembled in the machine abuts against a control arm 14 on the main operating shaft I, the roller, if permitted, tending to follow the arm 14 under spring action as hereafter explained during the initial stroke of the handle 4, which, as customary, is in the direction of the arrow A in Fig. 2.

A second arm 15 forms the operative connection with the pinion 55 of the mechanism, being formed with a slotted end 76 in which rides a ll carried by a link 18 in turn carried on the pivot of the pinion 55.

A pin 19 on the arm 15 and a second pin 80 on the link 78 are connected by a coil spring 8| which, during operation of the machine, maintains the pin TI to the right of the slotted end 15 as shown, and ensures that the setting rack 58 is maintained in the normal position during the depression of the column release keys towards the end of the ultimate return stroke of the main shaft, as is explained in the parent case. It will be noted that the position of the rocker Iii and of the pin in the slotted end 16 thereof as shown in the drawings is that when the handle 4 has been moved slightly forward without a key being depressed. Thus, if the handle is restored the slotted end would move across the pin 11 until the latter abuts against the opposite end to that shown, this slotted end therefore providing a lost motion to ensure proper zeroizing and to eliminate spacing strokes, as hereafter explained. It will be further noted, however, that when the pin H is at the opposite end of the slotted end 15, the spring 8! is under tension, thus enabling the lost motion to be taken up upon the handle again being moved forward.

A third arm 82 completes the rocker Hi, and is provided with an anti-friction roller 83 which cooperates with an oscillating lever 84 pivoted to the stretcher plate 28 at 85 to actuate a type bar of the printing mechanism described in the par ent case.

To enable the roller 13 to follow the arm 14 and the differentially geared actuating and setting mechanism to be substantially self-acting, the spring 64, in the normal position of the differential mechanism, is under tension so that when the setting rack 58 is unlocked, by releasing the column release key 32a, and the handle 4 is moved forward, the setting rack 58, the actuating rack 55 and the pinion 55, together with the rocker l0 automatically move rearwardly due to the tension in the spring 64, the roller 13 thus following the arm ?4, and the rate of the movement of the parts being governed by the movement of the handle. During the return stroke of the handle 4, the arm 14 abuts against the roller 13 to move the rocker 70 forwardly and Cal thereby restores the actuating mechanism against the tension of the spring 64. To facilitate the automatic movement of the parts and also to cause movement of the transfer rack 51 for a subtraction transfer as subsequently described, a further tension spring 6441. is provided connected between points on the stretcher plate 28 and the rocker 10, or the spring 64a, may be used in place of the spring 64.

Assuming that, in place of the column release key 32a shown depressed in Figure 2, the 8 numeral key is depressed and the operating handle 4 turned in the direction of the arrow A, the setting rack 58 and the actuating rack 56 will move to the left (Figure 2) the rocker 10 turning in an anti-clockwise direction as the arm 14 rotates away from the roller 13 until the respective abutment 63, i. e. the left hand one, engages the stub of the 8 key, when the further movement of the actuating rack 56 will be arrested and the arm 14 will leave the roller 13.

In this position the actuatingrack 56 will have moved a space equivalent to eight facets of the totalizer wheel 20, and if the wheel 20 through its pinion 68 be then engaged with the actuating rack 56 and the operating shaft I returned to its initial position, the totalizer wheel would show a reading corresponding with the item set up in the key column, 1. e. the number 8.

The engagement operations of the totalizer wheels 20 are fully described in the parent case.

When a totalizer wheel is passing from 9 to 0 in addition and 0 to 9 in subtraction, it is necessary to transfer one digit to or from the next wheel of higher denomination, and to do this each unit is provided with addition and subtraction transfer mechanisms, 94 and 95, respectively, each comprising a pair of bell crank levers mounted on a common pivot 96, see Fig. 3.

Each totalizer wheel 20 is provided at its left side see Fig. 2 with a pair of lugs 91 and 98, herein called the addition transfer lug and the subtraction transfer lug respectively. These lugs cooperate with the transfer mechanisms 94 and 95 of the left adjacent unit I2, i. e. the unit of next higher denomination, so that on a totalizer wheel 20 changing from 9 to 0 during addition, or from 0 to 9 during subtraction, the respective transfer mechanisms 94 or 95 of the next higher denom ination is actuated to add or subtract one, as the case may be to or from its wheel 20.

This transfer is effected, as previously mentioned, through the medium of the lower and normally stationary transfer rack 51 of the next higher denomination, by the mechanism now to be described, which is substantially in accordance with that disclosed in the specification of my U. S. Patent No. 1,838,209.

The addition transfer mechanism 94 of each unit, which it will be more convenient to describe first, includes a three-armed bell crank I00 having one arm I00w approximately at right angles to two forking arms I002), I 000, and pivoted at 96 to the right face of the stretcher plate 28, the arm I000, carrying a pin IOI projecting through a slot I02 in the stretcher plate 28 and engaging a co-operating notch I03 in the transfer rack 51 see Fig. 2.

Normally, the pin IOI engages the notch I03 and locks the transfer rack 51 in its neutral mid position. When an addition transfer is to be effected, the addition transfer lug 91 on the totalizer wheel of the next lower denomination engages the shorter arm I000 as it passes from 9 to 0 and rocks the bell crank I00 so that the pin IOI'moves down the slot I02 and out of engagement with the notch I03, whereat by movement of pinion 55 by the rocker 10 and under the action of the spring 64 Fig. 2, the transfer rack 51 moves forwardly i. e. to the right as viewed in Figs. 1 and 2 and permits the actuating rack 56 to turn the totalizer wheel 20 one tooth space in the direction of addition, whereby the next higher numeral reading is shown thereon.

The subtraction transfer mechanism 95 is also mounted on the common pivot 96 and includes a second bell crank I04 carrying a pin I05 passing through a slot I06 in the stretcher plate 28, and engaging a cooperating slot I01 formed in the transfer rack 51.

The slot I01 includes a pair of offset lateral branches I08, I09, the pin I05 normally lying at the head of the slot I01 adjacent the branch I08 and in abutment with the wall I08a terminating this branch, so that on the locking pin IOI of the addition transfer being removed from its notch I03, the transfer rack 51 is permitted to move by reason of the branch I08 passing along the pin I05, the dimensions of this branch being such .as to permit a movement of the transfer rack 51 corresponding to one tooth space of the actuating rack 56.

As shown in Figure 3, two retaining pawls I00d and I006 are provided for retaining the transfer mechanisms 94 and 95 in their operative positions when either addition or subtraction transfer is eifected. The retaining pawl I00d is pivoted at I00) to the stretcher plate, while the retaining pawl I00e is pivoted, as shown, to a lug I04a on the right-hand arm of the bell crank I04 of the subtraction transfer mechanism 95, the bell crank I00 of the addition transfer mechanism 94 being provided with a pair of outstanding lugs I00g and W071 formed with ratchet teeth for engaging respectively with the retaining pawls I00d and I00e. The pawls M001 and I00e are maintained in enagement with their respective ratchet teeth by means of springs I001 and IBM connected between points on the pawls and the bell crank I00, the spring I001 also serving to bring the subtraction transfer 95 into a condition for subtraction transfer when the bell crank I00 is rocked by a bail I I 0 actuated from the subtraction key as described in the parent case.

When the machine is set for addition, the addition transfer mechanism 94 is as shown in Figure 3, and thus, when the bell crank I00 is rocked for an addition transfer, the retaining pawl I00d drops into the first of the ratchet teeth on the lug I00g to maintain the bell crank in its rocked position.

When the machine is conditioned for subtraction, the bail IIO engaging with the arm I001: of the bell crank I00 is caused to rock the latter about the pivot 96, so that the pin IOI moves down the slot I02, and by reason of the spring I00 the bell crank I04 of the subtraction transfer mechanism 95 is simultaneously rocked about the pivot 96, thereby moving the pin I05 past the branch I09 down to the bottom of the slots I06 and I01. rack 51 has been released by the pin I0 I it is still maintained in its normal position by reason of the pin I05 engaging with the transfer slot I91 in the transfer rack.

Since the bell crank I 04 of the subtracting transfer mechanism has been rocked about the pivot 96 as explained above, the right-hand arm of the bell crank will be in a position to engage the transfer lug 98 of the next lower denomina- Thus, although the transfer tional totalizer wheel 20.' When, therefore, a subtraction transfer is to be effected, which is when the said wheel is passing through to 9, the lug 95 engages with the right-hand arm of the bell crank I04 to rock the latter and bring the pin I95 opposite the branch I09 whereby the transfer rack may be permitted to move to the left, the branch I09 running along the pin I05 until it is engaged by the wall I09a so that the actuating rack is moved one tooth space in the direction of subtraction. This movement is delayed until after the setting of the totalizer wheels so as to permit printing to take place first, by a transverse bail 32!) carried by arms 32I pivoted to the side frames of the machine, the bail 3223 being arranged by means of spring 322a to co-operatewith elongated notches 323 formed on the lower edge of each transfer rack 51 where in its normal or mid position it projects beyond the limits of the stretcher plate 28.

Mounted on the main shaft I is a full stroke pawl quadrant provided with a cam track 324, which, towards the end of the forward stroke, engages with the end of the bail 320 to rock the arms downwardly, thereby tensioning the springs 322a and bringing the bail 320 out of engagement with the notches 323, so that any transfer racks which have been set for transfer are shot to take one from the reading on their respective totalizer wheels 2!], it being understood, however, that the cam face 324 delays the release ,of the bail from the notches 323 until after the printing is effected.

It will be noted here, that for a subtraction transfer the transfer racks are moved rearwardly to effect the transfer by the spring 6411, which, upon the racks 5? being released by the bail pulls the rocker ID to the left. The upper rack 53 and the setting rack 58 are maintained stationary in the set position by the tension in the spring 64, so that the left hand movement of the rocker I0 and consequently of the pinion and actuating rack 56 causes the transfer rack 5-? to move to the rear with a 2:1 movement with respect to the actuating rack 56, until the pin H abuts against the right hand end of the branch slot H19, when one will have been subtracted fromv the totalizer wheel 20.

Further it will also be noted that when a subtraction transfer has been initiated, the pawl Ifllle will be engaging with the ratchet tooth on the lug ISM, and since the pawl Hind is already engaging with the second tooth on the lug I009 by of the rocking of the bell crank I00 by the bail Illl, both the subtraction and addition transfer mechanisms will be retained in operative position. so that the transfer rack can move immediately it is freed by the bail 320.

It will be understood that the actuating rack E being in engagement with the totalizer wheel during the forward stroke i. e. to the left, as seen in Figure 2 only for subtraction, and durthe rearward stroke i. e. to the right, as seen in Figure 2 only for addition, the resetting of the transfer rack 5'! at the end of the return stroke for addition only will not affect the totalizer wheel 29, since it is out of engagement with the actuating rack 56, as is explained in the parent The means employed for resetting the transfer rack to normal will also be explained subsequently, but it will be noted that when the transfer rack has effected a subtraction transfer, i. moved to the left during the forward stroke, it is brought back to its normal position by movement of the pinion 55 during the return stroke,

and is retained in said position by the left-hand wall of the branch slot I01 abutting against the pin I05, until such time as it is latched by the pin I95 or IQI.

It may be mentioned here, however, that when the totalizer wheel is brought out of engagement with the actuating rack 56, either at the end of the forward stroke for subtraction, or towards the end of the return stroke for addition, as is explained in the parent case, the consequent rocking of the bell crank 90 causes the pin Illfllc thereon to abut against the pawl mild, if transfer has taken place.

If the machine is set for addition, this will disengage the pawl IOOd from the first tooth on the lug g, and thus allows the bell crank ISO to be restored by the tension in the spring I002. On the other hand, if the machine is set for subtraction, that is the pawl mod, is engaging with the second of the ratchet teeth on the lug 500:; and a subtraction transfer has been effected, in which case the pawl Illfle will be engaging with the ratchet tooth on the lug M071, and an out standing lug I 501 on the pawl IOEie will be engaging with the pawl IOOd, then upon the pin 13k or" the bell crank 90 abutting against the pawl lead, the pawl I we will be disengaged from its ratchet tooth, and if the bail H0 has been restored, both transfer mechanisms 94 and 95 will be restored to normal, as shown, through the tensions in the springs IBM and I007 respectively and the pin it! on the bell crank I00 will consequrntly in the notch I03 in the transfer rack to lock the same.

Thus when the transfer rack 51 is restored during the return stroke of a subtraction cycle, the bell crank I04, due to the pawl I006 being disengaged, will rock in an anti-clockwise direction by the tension in the spring Iflflj, so that the pin I 95 moves down to the bottom of the slot I06 and the slot H11 in the transfer rack 51 to lock the latter in normal position and condition the bell crank I04 for effecting a subtraction transfer on any subsequent stroke, when necessary.

In regard to both addition and subtraction transfers it may be mentioned that when the machine is set for subtraction and a subtraction transfer is effected at the end of the forward stroke as has been described, the transfer racks 5'! are moved to the normal position during the return stroke and are latched in the said position firstly by the pins I05, on the bell cranks I M, moving down to the bottom of the branches ID! in the transfer racks 51, the pawls IOOe being disengaged by the totalizer wheels being out of mesh, and subsequently the transfer racks are locked in said normal position by the restoration of the bell cranks N30 to engage the pins IOI in the notches I63. It may be noted that when the transfer racks are moved to the normal position during the return stroke, the bail 329 snaps back into the notches 323 by the tension in the springs 322a, and further that the notches 323 permit the transfer racks to move to the right for addition transfer.

If the machine is set for addition, however, and an addition transfer has been effected, then since for addition, the totalizer wheels are in mesh on the return stroke, the transfer racks 5'! which have been shot will remain in the shot position, i. e. to the right by the tension in the springs 64. Consequently, it is necessary to restore such racks to normal if the whole of the differently geared actuating and setting mechanism is to be in normal position after each cycle of the main operating shaft I.

To thus ensure complete and automatic restoration of the actuating mechanism at the end of each complete stroke of the shaft I, and thereby eliminate the necessity for spacing strokes, the operating shaft I is provided with a series of short arms 330. Fig. 1.

When the setting racks 58 have been restored to their normal position towards the end of the return stroke of the handle 4, in addition, and just after the totalizer wheels 20 have been brought out of mesh with the actuating racks and the column release keys have been depressed to lock the setting rack 58 and the rack 53, the short arms 33!] come into abutment with pins 33! on the transfer racks 51 which have been displaced to the right for transfer. Further movement of the main shaft l towards its normal position thus causes these racks to be replaced into their mid positions and restoration of the actuating racks, the transfer racks being automatically latched by the pins Hll of the transfer mechanism.

Thus, whether the machine is set for addition or subtraction, the whole of its actuating and setting mechanism is restored at the end of each cycle of the main shaft in one operation.

From the foregoing it will be seen that by this invention very simple and effective means have been provided, for resetting displaced transfer racks during each cycle of the main shaft of the machine, thereby avoiding the necessityof the customary clearing stroke between each cycle.

Although the invention has been shown and described with reference to an adding and subtracting machine, it will be understood that it is equally well applicable to a machine which adds only and further that modifications in the constructional details can be made by those skilled in the art without in any way departing from the scope of the appended claims.

What I claim is:

1. In a calculating machine, the combination with totalizer wheels, each having an upper rack, a setting rack connected thereto, a normally stationary transfer rack and a pinion engaging with both of said upper and transfer racks, whereby movement of said pinion moves the upper and setting racks by an amount equal to twice the linear movement of the pinion, of means for moving the transfer rack out of its normal position in one direction to effect a transfer, a main operating shaft, an operative connection between the operating shaft and said pinion, and abut" ment means carried by said operating shaft so as to reset the transfer rack after said rack has been displaced to effect a transfer, and means for latching said transfer rack in the reset position.

2. In a calculating machine, the combination with totalizer wheels, each having an upper rack, a setting rack connected thereto, a normally stationary transfer rack and a pinion engaging with both of said upper and transfer racks, whereby movement of said pinion moves the upper and setting racks by an amount equal to twice the linear movement of the pinion, of spring means for moving the transfer rack out of its normal position to effect a transfer, a main operating shaft, an operative connection between the operating shaft and said pinion, and abutment means carried by said operating shaft so as to reset the transfer rack after it has been displaced to effect a transfer, and means for latching said transfer rack in the reset position.

3. In a calculating machine, the combination with totalizer wheels, each having an upper rack, a setting rack connected thereto, a normallyv stationary transfer rack and a pinion engaging with both of said upper and transfer racks, whereby movement of said pinion moves the upper and setting racks by an amount equal to twice the linear movement of the pinion, of co-operating addition and subtraction transfer levers operable by the totalizer wheels, said addition transfer levers engaging in notches in the transfer racks so as to latch the latter in the initial position, and said subtraction levers engaging in threearmed slots in the transfer racks, means for moving each rack for addition transfer, said movement being governed by the first arm of the slot, means for moving the rack for subtraction transfer, said movement being governed by the second arm of the slot and means for moving the subtraction lever into the third arm of the slot when the machine is set for subtraction to hold said rack until released for transfer, a main operating shaft, an operative connection between the main shaft and said pinion, and abutment means movable with the main shaft so as to reset the transfer rack into the initial position at the end of the return stroke of said shaft.

4. The structure of claim 3 and including abutments on each transfer rack formed by the third arms of said three-armed slots, whereby said racks are prevented from over-shooting the initial position when being reset after a subtraction transfer.

5. In a calculating machine, the combination with totalizer wheels, each having an upper rack, a setting rack connected thereto, a normally stationary transfer rack and a pinion engaging with both of said upper and transfer racks, whereby movement of said pinion moves the upper and setting rack by an amount equal to twice the linear movement of the pinion, a main operating shaft, and an operative connection between said main shaft and said pinion, of addition transfer levers operable by the totalizer wheels and normally engaging in notches in the transfer racks so as to latch the latter in the initial position, abutment means carried by the main shaft so as to reset displaced transfer racks into the initial position at the end of the return stroke of said shaft, and means for causing operated addition transfer levers to return to their latching position, whereby said reset racks are relatched.

6. In a calculating machine, the combination with totalizer Wheels, each having an upper rack, a setting rack connected thereto, a normally stationary transfer rack and a pinion engaging with both of said upper and transfer racks, whereby movement of said pinion moves the upper and setting racks by an amount equal to twice the linear movement of the pinion, of co-operating addition and subtraction transfer levers operable by the totalizer wheels, said addition transfer levers engaging in notches in the transfer racks so as to latch the latter in the initial position, and said subtraction levers engaging in threearmed slots in the transfer racks, means for moving each rack for addition transfer, said movement being governed by the first arm of the slot, means for moving the rack for subtraction transfer, said movement being governed by the second arm of the slot, and means for moving the subtaction lever into the third arm of the slot when the machine is set for subtraction to hold said rack until released for transfer, a. main operating shaft, and an operative connection between the main shaft and said pinion, of holding means engaging the transfer racks so as to hold said transfer racks from being displaced, means for releasing said holding means subsequent to the setting of the totalizer wheels, whereby transfer is delayed, abutment means carried by the main shaft so as to reset displaced transfer racks at the end of the return stroke of said main shaft, and means for causing operated addition transfer levers to return to their latching position, whereby said reset racks are relatched.

'7. In a calculating machine, the combination with totalizer wheels, each having an upper rack, a setting rack connected thereto, a normally stationary transfer rack and a pinion engaging with both of said upper and transfer racks, whereby movement of said pinion moves the upper and setting racks by an amount equal to twicethe linear movement of the pinion, of co-operating addition and subtraction transfer levers operable by the totalizer Wheels, said addition transfer levers engaging in notches in the transfer racks so as to latch the latter in the initial position,

and said subtraction levers engaging in threearmed slots in the transfer racks, means for moving each rack for addition transfer, said movement being governed by the first arm of the slot, means for moving the rack for subtraction transfer, said movement being governed by the second arm of the slot and means for moving the subtraction lever into the third arm of the slot when the machine is set for subtraction to hold said rack until released for transfer, a main operating shaft, and an operative connection between the main shaft and said pinion, of a holding bail engaging in notches in the transfer racks so as to hold said transfer racks from being displaced in one direction, the notches being formed to permit displacement of the transfer racks in the opposite direction, means for releasing said holding bail subsequent to the setting of the totalizer wheels, whereby transfer is delayed, abutment means carried by the main shaft so as to reset displaced transfer racks at the end of the return stroke, and means for causing operated addition transfer levers to return to their latching position, whereby said reset racks are relatched.

WILLIAM BALL. 

